The present invention relates to a monolithic disk-like element in material sensitive to magnetic attraction, for magnetic buttons.
Various types of magnetic buttons are known, which are adapted to be applied to leather goods such as e.g. handbags, and magnetic buttons which by virtue of particular provisions may also be applied to articles of clothing. Such magnetic buttons generally comprise a male element and a female element which are intended to be fixed onto two flaps which must be mutually associated. In particular, in a widespread solution the male element is constituted by a disk-like body in material sensitive to magnetic attraction, which has a cylindrical protrusion on its front face. The female element is manufactured substantially like the male element with the addition of a permanent magnet clinched or seamed onto its front face around its cylindrical protrusion. The permanent magnet is usually sintered and has the shape of a hollow cylinder so as to encircle said cylindrical protrusion of the female element, and has a greater height than said protrusion so as to define a cylindrical seat intended to also accommodate the cylindrical protrusion of the male element when the latter is arranged facing the permanent magnet. Both the male element and the female element have, on their rear face, fixing elements to associate the male and female elements with the two flaps of the material to be joined.
The Italian utility model patent application No. 21188 B/87, filed on 3/19/1987 in the name of the same Applicant, discloses a magnetic button of the type described above, provided in particular for articles of clothing. In this magnetic button the fixing elements are constituted by a tubular body which has, at one of its longitudinal ends, an outward expansion intended to be accommodated in a seat defined in the rear face of the male or female element. The edge of said seat is upturned on the widening of the tubular body so as to rigidly fix the tubular body to the male element or to the female element. The tubular body is inserted in the flap of fabric to which the male element or the female element must be fixed, and its opposite end with respect to the disk-like body is inserted in a hole of an elastic plate and is flanged outwards so as to couple the elastic plate and fix the disk-like body to the fabric. A cap may be located on the elastic plate and is covered by a dome seamed to the edges of the elastic plate.
This type of magnetic button, though it is particularly suitable for application to articles of clothing and ensures excellent sealing and resistance to humidity, is however relatively complicated to produce.
In the buttons of the considered type there are component parts involved in the main magnetic flux of the button and influencing the magnetic flux circuit and other component parts which are not involved or less involved in the magnetic flux. These other component parts are mainly destined to provide deformable elements for fixing the button on the fabric or leather of the article on which the magnetic button is destined to be applied. The fixing normally occurs by coupling together the fixing elements, such as by riveting deformation or the like. The trend in the art was heretofore to avoid to involve the magnetically involved component parts of the button, in the fixing or anchoring action, so that the fixing elements were entirely made of parts distinct from the magnetically involved parts. This trend was mainly due to the fact that fixing required deformation of the fixing elements, such as by riveting or the like, and it was feared that the subsequent deformation for the coupling purpose of the magnetically involved parts was likely to affect the magnetic flux circuit.
GB-A-2114208 and EP 0170852 show in particular the separation of the deformed fixing elements from the magnetically involved component parts. DE-A-2734218 and FR-A-582564 show male and female coupling types of fixing elements in non magnetic buttons in which the female configuration is socket-like and is not deformable, whereas the male configuration is tubular and is deformable at the moment when the coupling occurs.
It has been found according to this invention that the use of a non deformable socket type configuration in magnetically involved component parts of a magnetic button may solve the constructional, mounting, functional and economical and rationality problems of such type of buttons, without affecting the magnetic flux circuit.